First of all, the reference point of the image is its left, bottom corner. Furthermore, I just thought it would be nice to know some of the most used options that can be passed using the fifth parameter "string optlist".

Fitting the image into a virtual box<?php PDF_fit_image ( $pdf, $img, $x, $y, "boxsize {200 100} fitmethod meet" ) ?>Note: The box width and height (in Adobe points) would be given in the curly braces. Using the fitmethod "meet", the image would be ratio-scaled to be completely visible. Other methods are "clip" and "slice".

Multiple options can be used at the same time by simply concatenating them using a space. By the way, most pdf functions work exactly the same as the PDFlib functions. So just risk a look into the PFLlib documentations (use a search engine).